2024-03-29T07:01:09Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00030091
2023-11-16T02:43:16Z
499:508:509:2504
Contributions of residual hypoxemia to exercise hyperventilation in Fontan patients
Okamura, Yukiko
99312
Kito, Machiko
99313
Yasuda, Kazushi
99314
Baba, Reizo
99315
Fontan
exercise tolerance
oxygen uptake efficiency slope
maximal oxygen uptake
ventilatory response
2020-05
It is unsettled whether increased exercise ventilation in Fontan subjects is due to increased pulmonary dead space or augmented ventilatory drive. Twenty-six Fontan patients underwent symptom-limited treadmill cardiopulmonary exercise testing. Two groups of age- and sex- matched subjects served as controls: the biventricularly repaired (Bi, n = 18), and the “true” control (C, n = 29) groups. Peak oxygen uptake (VO2peak) was not different among groups (41.0 +/– 8.4 ml/min/kg, 43.5 +/– 6.6 ml/min/kg, and 45.9 +/– 11.6 ml/min/kg for Fontan, Bi, and C groups, respectively, p = 0.16). Fontan subjects, however, showed steeper alveolar ventilation/carbon-dioxide (VA/VCO2) regression slope (35.5 +/– 5.3, 28.7 +/– 3.8, and 29.5 +/– 3.0 l/ml, for Fontan, Bi, and C groups, respectively, p<0.0001), and lower end-expiratory carbon-dioxide fraction (FetCO2VAT) at ventilatory threshold (VAT) (4.4 +/– 0.5%, 5.5 +/– 0.5%, and 5.5 +/– 0.4%, for Fontan, Bi, and C groups, respectively, p<0.001). The dead-space ventilation fraction at VAT was similar among groups (0.33 +/– 0.06, 0.33 +/– 0.04, 0.35 +/– 0.05 for Fontan, Bi, and C groups, respectively, p = 0.54). In Fontan subjects, arterial oxygen saturation at rest (SaO2rest) was correlated with VA/VCO2 regression slope (r = –0.41, p = 0.04) and with FetCO2VAT (p = –0.53, p<0.01). We conclude that Fontan patients show exercise hyperventilation due to augmented central and/or peripheral ventilatory drive, which is further augmented by residual hypoxemia.
departmental bulletin paper
Nagoya University Graduate School of Medicine, School of Medicine
2020-05
Nagoya Journal of Medical Science
2
82
281
289
2186-3326
0027-7622
eng
http://www.med.nagoya-u.ac.jp/medlib/nagoya_j_med_sci/822.html
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